2.1 This test method provides a guide for evaluating the resistance of refractories in glass-melting furnace superstructures to vapor attack. This test method may also be useful for evaluating refractories in other applications where vapor attack occurs.

2.2 An electric-heated furnace is recommended. Water vapor and other atmospheric components in a gas- or fuel-fired furnace may participate in the chemical and physical reactions being studied. Results may differ, therefore, depending upon the nature and type of firing employed.

2.3 The degree of correlation between this test method and service performance is not fully determinable. This is intended to be an accelerated test method that generates a substantial degree of reaction in a relatively short amount of time. This acceleration may be accomplished by changing the composition and/or concentration of the reactants, increasing temperatures, or by performing the test in an isothermal environment.

2.4 Since the test method may not accurately simulate the service environment, observed results of this test method may not be representative of those found in service. It is imperative that the user understand and consider how the results of this test method may differ from those encountered in service. This is particularly likely if the reaction products, their nature, or their degree differ from those normally found in the actual service environment.

2.5 It is incumbent upon the user to understand that this is an aggressive, accelerated test method and to be careful in interpreting the results. If, for example, the reaction species have never been found in a real-world furnace, then this test method should not necessarily be considered valid to evaluate the refractory in question.